Coordinated control device for variable resistors

ABSTRACT

A device for coordinatedly controlling a plurality of variable resistors so as to achieve a desired combination of a plurality of variable resistors, said device comprising a first horizontal crosspiece having a lengthwise slot and a lateral plate perpendicular to the length of the crosspiece per se at each end thereof and second crosspiece having the similar slot and lateral plates the underside of which is partly on the same level as the underside of the first crosspiece when it is mounted on the second crosspiece, the two crosspieces being arranged crosswise and being moved relatively on a plane so that their movement moves a plurality of wipers so as to wipe the corresponding resistor elements.

United States Patent 1 [111 3,795,882

Tokubo Mar. 5, 1974 COORDINATED CONTROL DEVICE FOR 3,373,964 3/1968Bunders 240/81 R VARIABLE RESISTORS 3,244,868 4/1966 Goetz 240/81 R [75]Inventor: Tsugio Tokubo, Yokohama, Japan [73] Assignee: Teikoku TsushinKogyo Co., Ltd.,

Kawasaki-shi, Kanagawa-ken, Japan [22] Filed: Jan. 24, 1973 [21] Appl.No.: 326,194

[30] Foreign Application Priority Data May 6, 1972 Japan 47/44740 [52]US. Cl. 338/128 [51] Int. Cl H0lc 9/02 [58] Field of Search 338/128;74/471 XY [56] References Cited UNITED STATES PATENTS 2,950,892 10/1960Rick 240/73 BJ 3,629,775 12/1971 Kindred 3,662,313 5/1972 Komatsu1,781,203 11/1930 Teleki 2,621,503 12/1952 Schaefer 2,107,914 2/1938Stricker et a1. 240/73 B] 9/1950 Ford 240/81 R Primary Examiner-HaroldBroome Assistant Examiner-David A. Tone Attorney, Agent, or FirmLadas,Parry, Von Gehr, Goldsmith & Deschamps [5 7 ABSTRACT A device forcoordinatedly controlling a plurality of variable resistors so as toachieve a desired combination of a plurality of variable resistors, saiddevice comprising a first horizontal crosspiece having a lengthwise slotand a lateral plate perpendicular to the length of the crosspiece per seat each end thereof and second crosspiece having the similar slot andlateral plates the underside of which is partly on the same level as theunderside of the first crosspiece when it is mounted on the secondcrosspiece, the two crosspieces being arranged crosswise and being movedrelatively on a plane so that their movement moves a plurality of wipersso as to wipe the corresponding resistor elements.

13 Claims, 11 Drawing Figures COORDINATED CONTROL DEVICE FOR VARIABLERESISTORS BACKGROUND OF THE INVENTION This invention relates to a devicefor coordinately controlling a plurality of variable resistors to createany desired combination of resistances. More particularly, thisinvention provides a small-sized device with simple compact structurehaving a single handle for coordinated control of a plurality ofvariable resistors.

There has been growing demand for, an inexpensive simple device forcontrolling a plurality of variable resistors, which are useful in thefield of consumer electronics, especially for instance, in the casewhere volumes of a plurality of loud speakers are to be coordinatedlycontrolled so as to create a desired sound balance as in a stereo orqudraphonic speaker system. Various devices to achieve this purpose areknown.

A typical device of the prior art comprises a control stick or leversupported by a ball-and-socket joint which allows the nutation (joystickmovement) of the lever, and two U-shaped bridge-like supporters orbridge members having a lengthwise slot which are pivotably supportedhorizontally at right angles in a gyroscope-like fashion, whereby thelower end of the lever penetrates the slot of the two bridge members sothat the two bridge-members swing as the lever nutates. The ends of eachbridge member are provided with a wiper which respectively wipes thesurface of a resistor element which is placed perpendicular to therotation or swing axis of each bridge member when the bridge memberswings. In some cases, those bridge members directly contact thevariable resistors. Thus the desired resistance is determined by thedistance between the contact point of the wiper on the resistor elementand the lead terminal of either end of the resistor element for fourresistors in this case. However, the construction of the control deviceof this kind is complicated and therefore is inevitably bulky andcostly.

Another typical device of the prior art comprises a horizontally movablecrosspiece having a lengthwise slot and another horizontally movablecrosspiece having a lengthwise slot which is movable in a directionperpendicular to the direction of the movement of the first crosspiece,said two horizontal crosspieces being moved by means of a joystick thelower end of which is inserted in the slots of both crosspieces at thecrossing thereof, and contact means provided at the end of eachcrosspiece which slide along a resistor element as represented by U. 5.Pat. No. 3,629,775.

In the device of U. S. Pat. No. 3,629,775, the resistor element whichkeeps contact with one cross piece is not on the same level as that ofthe resistor element which keeps contact with another crosspiece, andtherefore the size of the device is inevitably large.

Prior to the present invention, I invented a device comprising a platemember horizontally movable in any direction and a plurality of wiperswhich move in accordance with the movement of the horizontally movableplate member in engagement therewith respectively maintaining contactwith a resistor. (U. S. Patent Application Ser. No. 249,241 filed May 1,1972) This device can achieve wide varieties of combination of aplurality of resistances very easily and very smoothly.

I have now invented a further improved device, which is the subject ofthis patent application. This device can provide more variedcombinations of a plurality of resistances with less play than thedevices of the prior art.

SUMMARY OF THE INVENTION According to this invention, a simple compactdevice for coordinatedly controlling a plurality of variable resistorsis provided, which comprises: a first horizontal crosspiece which has alengthwise slot and a lateral plate perpendicular to the length of thecrosspiece per se at each end thereof and is movable in the direction ofthe width thereof; a second horizontal crosspiece which has a lengthwiseslot and a lateral plate perpendicular to the length of the crosspieceper se at each end thereof, is shaped such that, when it is mounted onthe first crosspiece, the underside thereof is partly on the same levelas the underside of the lower one, and is movable in the direction ofthe width thereof; said two crosspieces being arranged crosswise withthe second crosspiece upon the first; a shaft which penetrates the slotsof the two movable horizontal crosspieces at the crossing thereof anddrives the crosspieces simultaneously in pair or all at a time; and aplurality of wipers which move in accordance with the movement of thetwo horizontal crosspieces maintaining contact with resistor elementsprovided on a common plane.

The stem or shaft may be a lever or joystick which is supported by aball-and-socket joint at the middle thereof, the lower end penetratesthe slots of the two crosspieces at the crossing thereof and the otherend functions as a handle. Or it may be a short shaft provided with aknob on its upper end, which can be moved horizontally.

Preferably a short cylindrical or annular member is placed in the slotsof the crosspieces at the crossing or intersection thereof, the lowerend of the joystick that forms a small ball is inserted in this shortcylindrical member, so that the crosspieces can be moved smoothly by thejoystick even when it deeply nutates.

Usually four wipers are used, each of which is supported on an insulatedbase plate at the one end thereof by an axis provided near the center ofthe base plate so that the other end thereof can rotate keeping contactwith a resistor element provided at the peripheral portion of the baseplate.

The crosspieces and the wipers have engaging means so that the wipersare moved as the crosspieces are moved. Usually protrusions are providedat suitable positions on the underside of each crosspiece and a slot orgroove is provided on the upper surface of each wiper, and a protrusionis placed in the slot or groove of the corresponding wiper. When thecrosspieces are moved each protrusion rotates the corresponding wiperBRIEF EXPLANATION OF THE ATTACHED DRAWINGS FIG. 1 is a partiallycut-away perspective view of a preferred embodiment of the device ofthis invention.

FIG. 2 is a cross-sectional view of the device of FIG. 1.

FIG. 3 is a plan view of the crosspieces and the base plane of thedevice of FIG. 1, partially showing the wip- BI'S.

FIG. 4 and FIG. 5 are plan views showing the positions 'of the wipers.

FIG. 6 is a perspective view showing construction of the wiper.

FIG. 7 and FIG. 8 are plan views of base plates showing otherarrangements of resistor elements.

FIGS. 9 through 1 1 represent another embodiment of this invention.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1, the above-mentionedcrosspieces are shown at 4 and 5. The shaft or joystick is shown at l.Member 15 is the base plate and member 3 is. a housing. The crosspiecesare designed so that they can move in the direction of the wodth thereofguided by a pair of facing lateral walls of the housing. The joystick lis supported at the middle thereof by a ball-and-socket joint 25provided at the center of housing. The ballshaped lower end of thejoystick 45 is inserted into a short cylindrical or annular member,which is placed in the slots 32 and 33 of the both crosspieces 4 and 5at the crossing thereof.

The arrangement of the crosspieces and the joystick will be betterunderstood by referring to FIG. 2 and FIG. 3. Each of the crosspieceshas a lateral plate on each end thereof, which slides along a wall ofthe housing 3. A lateral plate of a size as large as possible isdesirable as long as the plate does not restrict the movement of thecrosspieces. The lateral plates ensure stabilized smooth movement of thecrosspieces.

On the base plate 15, a resistor element is provided in a circular formnot true circle in this case as shown at 31 in FIG. 1.. The arrangementof the resistor elements will be better understood by referring to FIG.3 and FIG. 4. Members 16, 17, 18 and 19 are lead terminals.

As seen in FIG. 4, four wipers 7(11), 8(12), 9( 13) and (14) arerotatably secured to the base plate by axes 21, 22, 23 and 24, which arelocated near the center of the base plate 15. Consequently, the shape ofthe resistor element 31 is not a true circle but comprises four arcs thecenters of which respectively correspend to the axes of the wipers. I

Each of the wiper consists ofa finger and a finger carrier as shown inFIG. 6, in which (A) shows the finger carrier and (B) shows the finger.A finger has an axis hole and a slot (or a groove) 38, and a finger isfixed to the finger carrier by a suitable means.

On the other hand, the crosspieces have a pair of protrusionsrespectively 34, 35 and 36, 37 on the underside thereof. The pair ofprotrusions are usually provided at positions symmetric with respect tothe center of each crosspiece. But for a specific purpose, theprotrusions may be positioned asymmetrically to the center of thecrosspiece.

Thus, the housing 3 bearing the joystick l, the crosspieces 4 and 5, ashort cylindrical or annular member 6 and the base plate bearing wipersare assembled so that the each protrusion (34, 35, 36 or 37) of thecrosspieces placed in the slot or groove 38 of each finger carrier (7,8, 9 or 10), and the lower end of the joystick is inserted in theannular member 6 placed in the slots 32 and 33 of the crosspieces at thecrossing thereof.

With the thus assembled device, when the joystick takes the neutralposition, the wipers take positions as shown in FIG. 4. When thejoystick is nutated toward the corner C, for instance, the four wiperstake the positions as shown in FIG. 5. Thus by nutating orprecessionally moving the joystick to various positions, variouscombinations of resistances are obtained.

The construction and function of the device is explained in furtherdetail.

The base plate 15 is made of an insulating material, and a resistorcircuit 31 is provided thereon by printing for instance as shown in FIG.3, 4 or 5. The finger carrier 7, 8, 9 or 10 of the wiper has protrusions39 and 40 for instance and the finger has corresponding holes 41 and 42as shown in FIG. 6. The protrusions are to be caulked or swaged afterthe finger is placed on the protrusions. Each of thus formed wipers7(11), 8(12), 9(13) or 10(14) is supported by a conductive rivet 21, 22,23 or 24 as the rotation axis. The finger is pressed on both resistorelement and rivet by virtue of the resiliency of the bent body thereof,and slides on the resistor element. The rivets 21, 22, 23 and 24 aresecured to the base plate together with a common grounding terminal 20.

The crosspieces are designed so that one of them can be mounted onanother so as to be arranged crosswise but the underside of the uppercrosspiece is partly on the same level as that of the lower one so as tobe engaged with the wipers provided on a plane. As had been explainedabove, the crosspieces have a lateral plate on each end and it slides inthe direction of the width of the crosspiece along the walls of thehousing and the base plate 15. Of course the lateral plates are made ofan insulating material. Usually the lateral plates are formed integrallywith the crosspiece. The crosspieces are provided with small protrusions34, 35, 36 and 37 on the undersides thereof, which are respectivelyplaced in the slot or groove 38 of the finger carriers 7, 8, 9, 10 ofthe wipers. The range of movement of the crosspieces is determined bythe length between the lower end 45 of the joystick l and the fulcrum(ball) 2 thereof, the diameter of the opening 53 of the bearing member26 and the diameter of the part 52 of the stick 1. An annular member 6is loosely placed in the slots 32, 33 of the crosspieces at the crossingthereof, and the lower end 45 of the joystick is inserted in the annularmember.

The fulcrum (ball) 2 of the joystick l is tightly but rotatablysupported by means of bearing members 25 and 26 at the center of the topof the housing 3. When the joystick is operated, the crosspiece 4 movesin the direction of line Y Y' in FIG. 3, and the crosspiece 5 in line XX.

With respeect to FIG. 4 and FIG. 5 the operation of the device isexplained. FIG. 4 shows the positions of the four wipers when thejoystick takes its neutral position. If the joystick is nutated in theY'-direction, the lower end 45 thereof moves in a vertical planeincluding the Y Y line drawing an are. But this movement is converted toa horizontal movement in the Y- direction of the crosspiece 4 throughthe annular member 6. The Y-ward movement of the crosspiece 4 moves theouter ends of the wipers 7(11) and 8(12) in the Y-direction, the wipersbeing rotated around the axes or rivets 22 and 21 since the protrusions34 and 35 of the crosspiece 4 inserted in the slots of the wipers 7 and8 pull said wipers in the Y-direction. Thus the wipers 7 and 8(protrusions 34 and 35) will turn to the positions 34 and 35 as shown inbroken lines. Under this condition, if the joystick is not nutatedtoward the Y'-direction to the utmost, when the joystick is nutatedtoward the X-direction or X'-direction, the wipers 9 and 10 are moved inthe directions of the arrows shown in the figure, while the wipers 7 and8 (protrusions 34 and 35) remain at the positions 34 and 35. This meansthat one pair of resistances are kept constant and another pair ofresistances can be relatively changed.

If the joystick is nutated toward the corner C as in FIG. 5, the fourwipers will take positions as shown in FIG. 5. Suppose this device isused for a four-channel or quadraphonic stereo, and the terminals 17 and16 are connected to front speakers FS, and PS and the terminal 18 and 19are connected to rear speakers RS, and RS respectively. Then, under thecondition as explained above with respect to FIG. 4, the volumes of thefront speakers are diminished while the volumes of the rear speakers arerelatively changed. Under the condition represented by FIG. 5, thevolume of the C corner speaker is the largest and those of the otherthree speakers are diminished. This means balance of volumes of the fourspeakers can be regulated by nutating or moving the joystickprecessionally. When the joystick is moved to front and rear, volumes ofthe front and rear speakers are relatively changed and when the joystickis moved to right and left, the volumes of the right side speakers andleft side speakers are relatively changed. Thus, any desired balance ofvolumes can be obtained by selecting a suitable position of thejoystick.

As has been explained above, this invention has made it possible tocoordinatedly control a plurality of resistors by operating a singlelever or stick very smoothly without play of the working elements. Thedevice of this invention can be easily manufactured with fewer steps ofrequired circuit formation work. The device is also so simple andcompact that it will contribute to designing of stereo audio implements.

The invention of this application can be embodied in different ways asfollows, too. As to the shape of the resistors, a common tap or separatetaps may be provided in each resistor element as shown in FIG. 7 or FIG.8. For a specific purpose, a resistor element comprising four separateunits each having a tap as shown in FIG. 8 can be employed. In somecases, four sets ofa straight resistor element 55 and a straight currentcollector element 56 arranged in parallel with the former are providedalong the four sides of the base plate as shown in FIG. 9. Each resistorelement may or may not be provided with a tap. (FIG. 9 shows such taps.)In this case, on the underside of each of the crosspieces 4 and 5 issecured a short-circuiting member 57 instead of rotatable wipers asshown in FIGS. 10 and 11. By these arrangements, the purpose of thisinvention is achieved,

too.

What I claim is:

l. A device for coordinatedly controlling a plurality of variableresistors comprising: a first horizontal crosspiece which has alengthwise slot and a lateral plate perpendicular to the length of thecrosspiece per se at each end thereof, and is movable in the directionof the width thereof; a second horizontal crosspiece which has a lengthwise slot and a lateral plate perpendicular to the length of thecrosspiece per se at each end thereof, is movable in the direction ofthe width thereof and is shaped in a fashion that, when it is mounted onthe first crosspiece, the underside thereof is partly on the same levelas the underside of the first crosspiece; said two crosspieces beingarranged crosswise with the second crosspiece upon the first crosspiece;a housing along the inside surfaces of the side walls of which saidlateral plates of the crosspieces slide; a shaft which penetrates theslots of the two movable horizontal crosspieces and drives thecrosspieces simultaneously in pair or all at a time; and a plurality ofwipers which move in accordance with the movement of the two horizontalcrosspieces maintaining contact with resistor elements provided on acommon plane.

2. A device for coordinatedly controlling a pluraliy of variableresistors as set forth in claim 1, wherein four wipers are respectivelyrotatably supported by an axis provided on a base plate made of aninsulating material on which a resistor element or elements areprovided, and said wipers are moved in accordance with the movement ofsaid crosspieces by means of interlocking of protrusions provided on theunderside of the crosspieces and grooves provided on the upper surfaceof the wipers.

3. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 2, the shaft is ajoystick provided atthe center of the top ofa housing, the lower end of which penetrates theslots of the two crosspieces and the other end of which functions as ahandle.

4. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 3, wherein a short cylindrical member inplaced in the slots of the crosspieces at the crossing or intersectionthereof; and the lower end of the joystick that forms a small ball isinserted in this short cylindrical member.

5. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 2, the shaft is a short shaft with aknob at the upper end thereof, which is moved horizontally.

6. A device for coordinatedly controlling plurality of variableresistors as set forth in claim 5, the short shaft has a broad brim asthe guide for the movement thereof.

7. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 2, wherein a circular resistor elementwith four terminals is provided on the surface of the base plate and theend of each wiper sweeps a part of the resistor element when it isrotated around an axis provided near the center of the base plate.

8. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 7, wherein the resistor elementcomprises four separate arcuate units quadrantally arranged on the baseplate.

9. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 7, wherein the resistor element hastapping circuits.

10. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 8, wherein each resistor element unithas a tapping circuit.

11. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 2, wherein the wiper comprises a fingerand a finger carrier.

12. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 1, wherein the ing resistor element andcurrent collector.

13. A device for coordinatedly controlling a plurality of variableresistors as set forth in claim 12, wherein the resistor element unitshave tapping circuits.

* =l l =l

1. A device for coordinatedly controlling a plurality of variableresistors comprising: a first horizontal crosspiece which has alengthwise slot and a lateral plate perpendicular to the length of thecrosspiece per se at each end thereof, and is movable in the directionof the width thereof; a second horizontal crosspiece which has a lengthwise slot and a lateral plate perpendicular to the length of thecrosspiece per se at each end thereof, is movable in the direction ofthe width thereof and is shaped in a fashion that, when it is mounted onthe first crosspiece, the underside thereof is partly on the same levelas the underside of the first crosspiece; said two crosspieces beingarranged crosswise with the second crosspiece upon the first crosspiece;a housing along the inside surfaces of the side walls of which saidlateral plates of the crosspieces slide; a shaft which penetrates theslots of the two movable horizontal crosspieces and drives thecrosspieces simultaneously in pair or all at a time; and a plurality ofwipers which move in accordance with the movement of the two horizontalcrosspieces maintaining contact with resistor elements provided on acommon plane.
 2. A device for coordinatedly controlling a pluraliy ofvariable resistors as set forth in claim 1, wherein four wipers arerespectively rotatably supported by an axis provided on a base platemade of an insulating material on which a resistor element or elementsare provided, and said wipers are moved in accordance with the movementof said crosspieces by means of interlocking of protrusions provided onthe underside of the crosspieces and grooves provided on the uppersurface of the wipers.
 3. A device for coordinatedly controlling aplurality of variable resistors as set forth in claim 2, the shaft is ajoystick provided at the center of the top of a housing, the lower endof which penetrates the slots of the two crosspieces and the other endof which functions as a handle.
 4. A device for coordinatedlycontrolling a plurality of variable resistors as set forth in claim 3,wherein a short cylindrical member in placed in the slots of thecrosspieces at the crossing or intersection thereof; and the lower endof the joystick that forms a small ball is inserted in this shortcylindrical member.
 5. A device for coordinatedly controlling aplurality of variable resistors as set forth in claim 2, the shaft is ashort shaft with a knob at the upper end thereof, which is movedhorizontally.
 6. A device for coordinatedly controlling plurality ofvariable resistors as set forth in claim 5, the short shaft has a broadbrim as the guide for the movement thereof.
 7. A device forcoordinatedly controlling a plurality of variable resistors as set forthin claim 2, wherein a circular resistor element with four terminals isprovided on the surface of the base plate and the end of each wipersweeps a part of the resistor element when it is rotated around an axisprovided near the center of the base plate.
 8. A device forcoordinatedly controlling a plurality of variable resistors as set forthin claim 7, wherein the resistor element comprises four separate arcuateunits quadrantally arranged on the base plate.
 9. A device forcoordinatedly controlling a plurality of variable resistors as set forthin claim 7, wherein the resistor element has tapping circuits.
 10. Adevice for coordinatedly controlling a plurality of variable resistorsas set forth in claim 8, wherein each resistor element unit has atapping circuit.
 11. A device for coordinatedly controlling a pluralityof variable resistors as set forth in claim 2, wherein the wipercomprises a finger and a finger carrier.
 12. A device for coordinatedlycontrolling a plurality of variable resistors as set forth in claim 1,wherein the resistor element comprises four straight units squarelyarranged on the surface of the base plate in combination with parallelcurrent collectors, and a short-circuiting means is provided at each endof the two crosspieces, which keeps contact with the correspondingresistor element and current collector.
 13. A device for coordinatedlycontrolling a plurality of variable resistors as set forth in claim 12,wherein the resistor element units have tapping circuits.